1995 Blazer rear speakers not working.NAPA shows a relay for speakers. Would this be my problem ? if so where is this relay located ?

The wires provided for a radio system are as follows:
yellow = hot with ignition key ON
orange = hot from BATT at all times
Grey = dimming power from instrument panel

Black = ground

Harness Wires provided for the speakers as follows:
Left rear speaker = +brown -yellow
Right rear speaker = +dark blue - light blue
Left front door speaker and tweeter = +tan - grey
Right front door speaker and tweeter = +light green -grey
Note: connection colors at the speaker location differ as noted:
Right front door = +brown -yellow
Left front door = +brown -yellow
All other speaker connections are consistent with their harness colors.

Click Here for wiring diagram information

On my expedition it is located behind the spare tire in front of the fuel tank. Small bracket holding it up there. If you go to a CARQUEST/NAPA/Oreilly parts store they will be able to show you a picture of where it is.

If your 1995 Chevrolet Blazer shows code P19DA, it means that there is a signal problem between the fuel pump and the PCM. This may have happened because you have a burned fuel pump motor, or the float meter of the fuel pump has a burnt wire.
Check the fuel pump relay, if malfunctioning, inspect the ground circuit to and see if the resistance is accurate. If it appears to be damaged, remove the fuel tank, taking out the pump, and replacing it with one that works.

Hi there:
Check this on 1998 Chevrolet S10 Blazer Car Stereo Radio Wiring Diagram:

Car Radio Constant 12v+ Wire: Orange
Car Radio Switched 12v+ Wire: Dark Green
Car Radio Ground Wire: Black
Car Radio Illumination Wire: Gray
Car Stereo Dimmer Wire: Violet/White
Car Stereo Antenna Trigger: N/A
Car Stereo Amp Trigger Wire: N/A
Car Stereo Amplifier Location: N/A
Front Speakers Size: N/A
Front Speakers Location: N/A
Left Front Speaker Positive Wire (+): Tan
Left Front Speaker Negative Wire (-): Gray
Right Front Speaker Positive Wire (+): Light Green
Right Front Speaker Negative Wire (-): Dark Green
Rear Speakers Size: N/A
Rear Speakers Location: N/A
Left Rear Speaker Positive Wire (+): Brown
Left Rear Speaker Negative Wire (-): Yellow
Right Rear Speaker Positive Wire (+): Dark Blue
Right Rear Speaker Negative Wire (-): Light Blue

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Hi natgonzo, your Blazer doesn't use a starter relay, it only has a starter solenoid which is attached to the top of the starter motor. Hope this helps.

Please rate my advise.

The fuel pump relay in my blazer is located in the rear of the glove box which means you have to clean out all of the maps and other junk to get to it. There is a plastic cover that has to be removed to expose the relay which is the right side of the two present.
You can tell if it is operating when you turn the ignition key to "ON", the relay will click and you should hear a humming sound as the fuel pump energizes.

2000 Chevrolet S10 Blazer Car Stereo Radio Wiring Diagram
Car Radio Constant 12v+ Wire: Orange
Car Radio Switched 12v+ Wire: Dark Green
Car Radio Ground Wire: Black
Car Radio Illumination Wire: Gray
Car Stereo Dimmer Wire: Violet/White
Car Stereo Antenna Trigger: N/A
Car Stereo Amp Trigger Wire: N/A
Car Stereo Amplifier Location: N/A
Front Speakers Size: N/A
Front Speakers Location: N/A
Left Front Speaker Positive Wire (+): Tan
Left Front Speaker Negative Wire (-): Gray
Right Front Speaker Positive Wire (+): Light Green
Right Front Speaker Negative Wire (-): Dark Green
Rear Speakers Size: N/A
Rear Speakers Location: N/A
Left Rear Speaker Positive Wire (+): Brown
Left Rear Speaker Negative Wire (-): Yellow
Right Rear Speaker Positive Wire (+): Dark Blue
Right Rear Speaker Negative Wire (-): Light Blue

1995 Nissan Pathfinder Car Stereo Radio Wiring Diagram
Car Radio Constant 12V+ Wire: Pink
Car Radio Switched 12V+ Wire: Blue
Car Radio Ground Wire: Gray
Car Radio Illumination Wire: Red/Blue
Car Radio Dimmer Wire: Red/Yellow
Car Radio Antenna Trigger: N/A
Car Radio Amp Trigger Wire: N/A
Front Speakers Size: 5′ x 7′
Front Speakers Location: Doors
Left Front Speaker Wire (+): Pink
Left Front Speaker Wire (-): Blue
Right Front Speaker Wire (+): White
Right Front Speaker Wire (-): Black
Rear Speakers Size: 5′ x 7′
Rear Speakers Location: Roof Mount
Left Rear Speaker Wire (+): Light Green
Left Rear Speaker Wire (-): Purple
Right Rear Speaker Wire (+): Blue
Right Rear Speaker Wire (-): Pink

you have to put a guage on it to find out the pressure it may kick on but not enough pressure